Sheath and method of manufacturing same



June 14, 1960 J. Q. ADAMS ETAL SHEATI-I AND METHOD OF MANUFACTURING SAME Filed June 13, 1956 United States John Q. Adams, Paterson, and Wesley J. Howe, Hohokus, NJ., assignors to Becton, Dickinson and Company, Rutherford, NJ., a corporation of New Jersey Filed June 13, 1956, Ser. No; 591,059

S Claims. (Cl. 12S- 218) This invention relates to a structurally and functionally improved sheath especially intended for association with the top of a hypodermic syringe or to enclose the shank of a hypodermic needle. The invention also contemplates an improved method for the manufacture of a shield of this type.

By means of the present teachings, a sheath is furnished which, after the parts have been cleaned, may be applied to a hypodermic syringe barrel or to a cannula. Thereupon, the assembly may be disposed in an autoclave with assurance that complete sterilization will be achieved and no displacement of the sheath will occur. Therefore, in a syringe assembly no conditions of vacuum or pressure buildup will be encountered; the assembly being capable of storage for long periods of time Without danger of the parts enclosed within the tip becom.

ing contaminated.

Moreover, a sheath or shield embodying this invention may' be manufactured at a relatively nominal figure and by means of procedures which are capable of practice by relatively unskilled operators. The resultant device will be adequately rugged and capable of maintaining a sterile condition of the parts for indefinite periods of time.

With these and other objects in mind, reference is. had to the attached sheet of drawings illustrating practical embodiments of the invention and in which:

Fig. .1 is a side elevation of a syringe assembly with the sheath applied thereto;

Fig. 2 is a side elevation in enlarged scale of the sheath illustrated in Fig. 1;

Fig. 3 is an end view of the unit;

Fig. 4 is a longitudinal sectional view taken along the line 4-4 in the direction ot the arrows as indicated in Fig. 2;

Fig. 5 is a somewhat diagrammatic sectional side view of apparatus by means of which the method of manufacturing shields may be practiced;

Fig. 6 is a transverse sectional view taken along the line 6-6 in the direction of the arrows as indicated in Fig. 5; and

Fig. 7 is a side elevation of a further shield especially useful when employed to enclose a hypodermic needle.

Referring primarily to Fig. l, the numeral 10 indicates the barrel of a hypodermic syringe which adjacent its rear and open end is prodvided with a iiange 11. Extending into the fore of the barrel is a plunger 12 having an actuating portion 13. The forward end of the barrel terminates in a tip which is preferably integral with its body. All of these several parts are conveniently formed of glass. The integral tip portion has been indicated at 14 and may amount a fitting 15. That fitting is ordinarily of metal and formswhat is commonly known as a Luer coupling to receive and retain the hub of a hypodermic needle.

In order to maintain the sterility of the exterior surfaces it has been customary to mount upon the syringe tip a cap which protects the parts. Aside from the ex- 2,940,445 Patented Ilune 1'4, A196C? Where attempts were made to apply the capsto the syringe tips after autoclaving, the expense was obviously` increased incident to the care which had .to beV exercised and time necessary to such a procedure.

Where a sheath is involved which is to be applied to the syringe tip, a form of contruction found to be espically desirable is illustrated in Figs. 2, 3 and 4. lThis will involve a body 16 .preferably'formed of'vinylplastic which will be nonetoxic and non-pyrogenic. The rearor. tubular end of this body will embrace a diametersuch that it may be received within the bore of iitting 15. In=

any event, it should intimately embrace the tip 14 of the syringe so as to furnish a protective cover for the surfaces of the latter and irrespective of whether a metallic fitting is present or not. The forward end of the sheath may be attened as at 17 and provide a pair of bores or passages 1S, one to each sideof the axis 0f the unit, or holes adjacent the end portion of theV tube. The one or more apertures are closed adjacent their inner ends by `a pledget 19 of preferably non-absorbent cotton.` As espef cially shown in- Fig. 4, this plug will extend rearwardly. within the bore of body 16 for a suitable distance, so that.

it will provide a proper filter in thecaseof flow of air, gas or steam under pressure. lts length should not be so great that upon application of tube 16 to the syringe tip 14, the edge zone of the latter will substantially' comfi press the pledget.

A similar type of shield has been illustrated in'Fig. 7v

in which a relatively long tubular body has been indicated at 20. .One end of this body is attened to dene a con-v stricted bore portion 21 which may extend in line with.

its axis and to either side of whichconstricted zones in the form of'ns 22 exist. It will be apparent that the.

constriction might include numerous other congurations.

The opposite end of tube 20 deiines a bore diameter such;A that it may frictionally embrace the hub 23 of a cannula.

24. The body of the latter will be housed within the bore of tube 20. Hub 23 may be mountedupon a syringe.

tip, provide the end of ablood donor assembly be being coupledto the end of a suitable tube, or embrace the soleum't which is initially associated with the needle.

.The bore of body 26 may be lled with cotton robing. indicated at 25. This material, in common with the.

pledget, should be preferably non-absorbent. In manufacturing sheaths of this type, as shown in Fig. 7, an apparatus such as has been schematically shown in Fig. 5 may be employed. That apparatus will produce vinyl tubing by what might be an extrusion process. It will include, for example, an encasing member 26 within which a screw 27 turns in any desired and acceptable manner to feed the material. The casing terminates in a discharge nozzle 28 concentrically disposed with respect to and spaced from a tube 29. The latter has its delivery end adjacent the edge of the nozzle. This tube in conjunction with the nozzle will denne an annulus such that if the material 30 is expressed from the member Q6, a vinyl plastic tube 31 will be formed. This tube will have the required diameter which, due to the characteristics of the material, will enable it to t (within limits) needle hubs or similar portions embodying diierent diameters.

T here is fed through the tube 29 a body of cotton robing 32, which in the nished unit illustrated in Fig. 7 is identified by the numeral 25. It is apparent thatif, as illustrated, this material be arranged in the form of a 3,1.V In any event, itYwill be encased bysthat tube.VV

Y. .Y TheV latter may be severedinto suitable Ylengths asV it is discharged from Vthe nozzle by, for example, a pair of cutting blades 33. Conveniently operating'insynchronisin with these-'blades are forming jaws 34. "The latter, especially as shown in'Figf, have theircooperating faces Y continuous strand, it Will completely iill the bore of tube v 2,940,445' j Y' f outer Y'sheath end embody'a configuration such that this unit be retained against accidental displacement therein.

I claim:

1. A sheath for protecting parts of a hypodermic asi sembly, said sheath comprising a tubular body having an Y open end to engage with surfaces of such parts, the sheath recessed rIfhis Will'res'ul'tin the kformation Vof bore porf Y Vtion`21. Also,-du'e tothecamniing action produced as Y Yjaws 34 move towards each other the material of the'roving will be constricted Within the smaller diameter oi bore 21.1 rSo constricted Yit will he held against displacef ment within th'extuhe bodyt).

It is apparent that in Yboth Vof* the sheaths illustrated 1 Yan adequate passageexists `for the escape of gasesand the "110W 'of steamintathe interior ofthefs'hield soithat com- Yplete sterilizationLof the parts is assured by an autoclavtin' 'asabai'rirtoair borne bacteria.' With a sheath apshield Vor sheath may specifically he 'a cci-polymer of vinyl chloride.y YRegardless of whether Vthe shield isl applied to Ythe tip Y14 of'asyringe or the tip defined by Va hub such as 23, it Yshould be mountedin'sealingrelation tothe surface questionwhile the partsare still wet.

'Y inthe caseotY asyring'e assembly, 'the plungerrlZ will, of course",`be fully.Y projected Y'or seated'in thebarrel prior Ytozapplication ofthesheath or shield. The will prevent contamination.'Y In [the case of the structure shown in Y Figs. 1 through Y4, the passages 18 will furnish Vopenings to either side of the sealed zone 17 to allow for proper venting of and .passageY of steam or gas during sterilization.

being ilattened adjacent its ofipsite end and such ilatten-v ing being limited to an area such that at leastone passage for the 'ow ofY gases exists through said opposite end.

2. In a sheath as detinedin claim l, a body of` fibrous material Within said sheath and .partsfof said material be;

ing constricted within the flattened end vzone of said sheath i Vto retain s'uh material against displacement.,l

3. In combinatiom; ,a'hypodermicneedleV having a pointed end, a hub secured tozsaid'needle in spaced relas tionship to its point, a* tubular sheath having an open Y inner end, the bore surface adjacent such end sealingly Y Vpassages,adjacent that end which is opposite saidl tip struc-V ture, and the adjacent end zone'of said sheath being vflat-V l The Vsamevvill be true of the single passage Z1 in the case ofthe structure shown in Fig. 7. Y Y

ItV wilLof course,.be understood that various materials i might beputilized i to provide aV `sheath and/or iilte'ng structure.` VFor example,-1nylon could be employed Where ydrygrheat sterilization is,ifequired. ThisV would involveV approximately Y320 I". for a period jofone hour. f` ilscg,w

` with fsuch "material, Ya non-absorbent"glassiiber filter,VV 'Y jwould in -many'instances'be satisfactory; YWhereygas sterilization is zto be. employed, polyethylene as a sheath lmaterial wouldbe satisfactory. Y Also, non-absorbent Vcotton robing'could be utilized as a `filter; Injevery instance 5' wheretthe pledget is-introducedinto the sheath after the tubing has beenY formed, it is delnitely preferred that the engaging the surfaces of said hub, saidY sheath extending around and beyond the pointed needle end andrbei'ng attened at its outer end and such attening beinglimit'edA to an area such Vthat at least one passage ,for the flow of gases exists through such outer end. Y

4. In a hypodermic assembly in combinationra bored Y,tip structure, a sheath embracing a tubular 'body yreceiving said tip structure,VV said sheath being formedV with an opening adjacent that end which is opposite said tip structure and relatively depressed portions integral with said sheath and embracing compressed paits to both sides of said opening.

. 5. VIn a hypodermic vassen'ibly in combination' arbored 'stip structure, a sheath embracing a tubular body receiving said structure, said sheath being formed with a pair-,of

Vtened to furnish an air-impervious part intermediate said passages.V y Y Y References Cited in the le of Ythis patent Ursu'raiv STATES PATENTS .Y

Y l. OTHER REFRENCS f Y Dental Bigest, June 1943, vol. 9, No. 6, (pp: 275; 2778.) (Co'py in Div. 55, classV 12S-218;) Y 

